Materials Data on Eu(MgAs)2 by Materials Project
Eu(MgAs)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Mg2+ is bonded to four equivalent As3- atoms to form MgAs4 tetrahedra that share corners with six equivalent EuAs6 octahedra, corners with six equivalent MgAs4 tetrahedra, edges with three equivalent EuAs6 octahedra, and edges with three equivalent MgAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–54°. There are three shorter (2.68 Å) and one longer (2.74 Å) Mg–As bond lengths. Eu2+ is bonded to six equivalent As3- atoms to form EuAs6 octahedra that share corners with twelve equivalent MgAs4 tetrahedra, edges with six equivalent EuAs6 octahedra, and edges with six equivalent MgAs4 tetrahedra. All Eu–As bond lengths are 3.17 Å. As3- is bonded to four equivalent Mg2+ and three equivalent Eu2+ atoms to form a mixture of distorted corner and edge-sharing AsEu3Mg4 pentagonal bipyramids.